Electrical switch contact structure with improved inflatable bladder actuating means

ABSTRACT

An electrical switch for large amperage currents including R.F. currents, which includes first and second contacts and a shorting means comprising a plurality of discs.

1 Unlted States Patent 13,569,649

[72] Inventor Arnold A. Spielbauer [56] References Cited Richardson, Tex. UNITED STATES PATENTS [21] P 1969 1,853,506 4/1932 Carter 200/166(B2) [221 d g- 9 11971 2,795,668 6/1957 Puckett 200/86(.1)X [451 C f C 2,884,503 4/1959 Connelly 200/16(.l)X [731 Assgnee 2 3,168,635 2/1965 Gebhart 200/166(B2) 3,170,048 2/1965 Glatz et a1 200/11 3,197,579 7/1965 Romney.... 200/166(B2)X Hauser WITH IMPROVED INFLATABLE BLADDER Primary ExaminerR0bert K. Schaefer ACTUATING MEANS Assistant Examiner-J. R. Scott 3 Claims, 3 Drawing Figs- Attorneys-Henry K. Woodward and Robert J. Crawford [52] US. Cl 200/83,

200/16, 2001166 [51] Int. Cl ..H0lh 15/00, HOlh 35/40, l-IOlh 1/00 [50] Field of Search 200/ 16.1, ABSTRACT: An electrical switch for large amperage currents 83.2, 83.8, 86, 86.1, 166-(Bl 166 (B2), 166 including R.F. currents, which includes first and second con-1 (B8), 1 1 tacts and a shorting means comprising a plurality of discs.

I O e PATENTED m 9l97l 569549 36 FIG. 3 uvvsrvron. ARNOLD A. SPIELBAUER BY 54% am/M ATTORNEY This invention relates to electrical switches, and more particularly to electrical switches for large amperage currents, including radio frequency (R.F.) currents.

Relatively large conductive contacts are required to switch currents of considerable amperage. Further, to prevent arcing and burning of the contacts, a firm electrical connection must be made between the contacts when the switch is closed. Another design consideration for R.F. switches in particular is the prevention of introducing R.F. resonances of the fundamental R.F. frequency which may produce a damaging standing wave voltage in the circuit. i

Accordingly, an object of this invention is an improved electrical switch for accommodating large currents.

Another object of the invention is an electrical switch which minimizes arcing and heating effects when closed.

Still another object of the invention is an improved switch for R.F.'currents which does not present R.F. resonances in the circuit.

A feature of the invention is means for providing a firm connection between contacts which maynot be in accurate alignment.

These and other objects and features of the invention will be more fully understood from the following description and appended claims.

Briefly, the electrical switch includes first and second electrically conductive contact members which may be two metal plates for accommodating large electrical current. Edges or other suitable portions of the platesare positioned in substantially parallel spaced arrangement and provide the switch contact surfaces. A support member, in substantially parallel relationship with respect to the contact portions of the electrically conductive members and spaced therefrom, supports a plurality of electrically conductive disc members with the disc members having an inside diameter greater than the outside diameter of the support member. For closing the switch, actuation means is provided for urging the support member towards the contact portions and the disc members into engagement with the contact portions. Each disc is able to seek a firm contact in engaging the contact portions.

The invention will be more fully understood from the following detailed description and appended claims when taken with the drawing, in which:

FlG. 1 is a perspective view of an electrical switch in accordance with the invention; 7

FIG. 2 is a side view in section of the electrical switch shown in FIG. 1; and

FIG. 3 is a view in section of the contact closing means for the switch shown in FIG. 1.

Referring now to the drawings, FIG. 1 is a perspective view of an electrical switch in accordance with the invention and includes conductive plates and 12 which function as the switch contacts. The metal plates, aluminum or other suitable electrically conducting material, are utilized as the switch contact in order to accommodate high amperage currents. Edge portions 14 and 16 of plates 10 and 12, respectively, are arranged in substantially parallel, spaced relationship and receive shorting means when the switch is closed. A shorting member shown generally at 18 is mounted between plates 10 and 12 and is yieldably biased by spring 20 away from edge portions 14 and 16. Shorting member 18 includes a plurality of electrically conductive discs 22 which are uniquely arranged on a support member and short edge portions 14 and 16 when the switch is closed.

Referring now to FIG. 2, a side view in section of the electrical switch of FIG. 1 is illustrated. Mounted between plates 10 and 12 is an insulating support block 24 which has a concave portion for supporting a metallic housing 26. Housing 26 ac; l

commodates an inflatable air bladder 28, and an air line 30 extends through block 24 and housing 26 to connect the inflatable bladder 28 to an air supply (not shown).

Shorting means 18, shown in a switch deactuated position,

is yieldably biased away from edge portion 14 and 16 and rests on housing 26. Shorting means 18' includes an inner support member 32 which may be a cylinder (as shown), rod, or the like. Mounted on the support member 32 are the conductive discs 22. It will be noted that the inside diameter of each of the conductive discs is larger than the outside diameter of the support member 32, which allows the discs 22 a limited amount of free motion with respect to support member 32. This feature of the invention permits firm contact to be made along and between the edge portions 14 and 16 when the switch is closed, as indicated by the dotted position for the discs 22. Since the edge portions 14 and 16 may be uneven and/or not parallel to each other, a solid shorting member, for example a solid rod, would not permit a firm electrical contact along and between the edge portions. However, since discs 22 do have a limited amount of free motion with respect to support member 32, each disc is allowed to seek a firm contact between the edge portions 14 and 16 when the switch is closed.

Closing of the switch is effected by inflating air bladder 28 which urges shorting means 18 away from housing 26 and towards the edge portions 14 and 16 of plates 10 and 12, respectively. Because of the pliability of the air bladder, the movement of one of the conductive discs 22 is not limited by the travel of other discs 22, thus allowing each disc to move into firm engagement with the edge portions 14 and 16 despite unevenness of the edge portions.

FIG. 3 is a view in section of shorting member 18. Discs 22 are preferably separated by spacers 36 which facilitate ease of disc movement on support member 32. Plugs 38 are inserted in either end of support 32 and include projections 40 on which one end of the spring bias means is supported. Spacers 42 are provided between the plug 38 and washers 22.

It has been found that switches in accordance with the present invention accommodate currents of large amperage without arcing or overheating. Further, it has been found that the plurality of individual discs has very little self-inductance and does-not introduce an RF. resonance into the circuit, thus the switch is especially well suited for switching R.F. currents. Accordingly, the switch has been advantageously employed in high power radio transmitters.

While the invention has been described with reference to a specific embodiment, the description is illustrative and not to be construed as limiting the scope of the invention. Various modifications and changes may occur to those skilled in the art without departing from the spirit and scope of the invention.

Iclaim:

1. An electrical switch comprising first and second electrically conductive contact members, said first and second contact members having first and second portions, respectively, in substantially parallel, spaced arrangement, a shorting means in substantially parallel, spaced relationship with respect to said first and second portions, said shorting means including a support member having an outside surface defined by a first diameter, a plurality of electrically conductive disc members supported by said support member, said disc members having an inside diameter greater than said first diameter of said support member, actuation means for urging said disc members into engagement with said first and second portions of said first and second contact members, and biasing means yieldably urging said shorting means away from said first and second portions when said actuation means is deactuated.

2. An electrical switch as defined by claim 1 and including spacer members mounted on said support member and separating each of said disc members.

3. Anelectrical switch as defined by claim 1 wherein said actuation means includes an inflatable bladder. 

1. An electrical switch comprising first and second electrically conductive contact members, said first and second contact members having first and second portions, respectively, in substantially parallel, spaced arrangement, a shorting means in substantially parallel, spaced relationship with respect to said first and second portions, said shorting means including a support member having an outside surface defined by a firSt diameter, a plurality of electrically conductive disc members supported by said support member, said disc members having an inside diameter greater than said first diameter of said support member, actuation means for urging said disc members into engagement with said first and second portions of said first and second contact members, and biasing means yieldably urging said shorting means away from said first and second portions when said actuation means is deactuated.
 2. An electrical switch as defined by claim 1 and including spacer members mounted on said support member and separating each of said disc members.
 3. An electrical switch as defined by claim 1 wherein said actuation means includes an inflatable bladder. 